1. Field of the Invention
The present invention relates to pumps and more particularly to the priming of residential and industrial pumps.
2. Description of the Related Art
One of the rituals of cottage life in North America is priming the water pump in the spring. This usually involves lugging many pails full of water up to the cottage from the lake or the well. The water is then poured down the priming hole of the pump, usually spilling everywhere, in an attempt to fill the suction line and pump with water to remove the air from the system, and thereby to prime the pump. The process can be very difficult, particularly with long suction lines running over irregular ground that are prone to trapping air in high spots in the line and this often results in many hours of priming time.
There are several known methods to prime cottage pumps such as using hand or electric pumps to fill the suction line with water at the foot valve, and hand pumps attached to the pump to pull water up the suction line by creating a vacuum in the pump. With any of these systems, however, air can still remain trapped in the high spots in the line and there is no way to tell if priming is complete and the process may still need to be repeated several times.
The priming of industrial pumps is often accomplished by using powered vacuum pumps to suck water up the line, using ejector pumps installed downstream of the pump that are driven by compressed air or another source of water to create a vacuum sucking water up through the pump, and using auxiliary submersible priming pumps to fill the lines and prime the pump.
There are several so-called `self-priming` water pumps currently available for cottages and farms. However, it is still necessary for the operator, in some cases, to fill the suction line with water and it is often necessary to add more water to the pump during the priming cycle. Moreover, these so-called `self-priming` pumps are not intended to improve the priming operation of the many thousands of conventional pumps already in use.
U.S. Pat. No. 5,356,274 entitled SUPPLYING SELF SUCTION UNIT describes a self priming pump system. In this arrangement, storage tanks are required on the suction and discharge sides of the pump. These tanks are required to retain priming fluid at all times to prime the system but the size of the tanks required to hold sufficient priming fluid to prime the system in the event of a loss of prime and withstand the operating pressures of the systems would make them an expensive solution for cottage or farm installations.
U.S. Pat. No. 4,780,050 entitled SELF PRIMING PUMP SYSTEM describes a system to self-prime pumps and in particular, aircraft fuel pumps. The system has a priming reservoir above the pump with a bypass line from the reservoir tank to the pump to wet the impeller so that the pump can operate at all times and retain its prime using fluid from the reservoir. While this system will generate a partial vacuum to prime the fuel pump effectively, no provision is made to accommodate high lifts typical on cottage water systems or many industrial applications.
U.S. Pat. No. 4,934,914 entitled PORTABLE MOTOR PUMP describes a pump to drain residual water from a ground-level source, such as a puddle on a street, and to accommodate air accompanying the residual water. The pump has a self priming feature by way of a pump which is located within an outer casing full of water to maintain a flooded condition at the impeller, similar to a conventional submersible pump. As in the case of the fluid pump mentioned above, no provision is made to remove air and, at the same time, to generate sufficiently high vacuums capable of very high lifts, such as for example over 20 feet.
These aforementioned pump arrangements and other residential pump systems have difficult, expensive, or inadequate priming methods for very high lifts. They often require the suction line to be initially filled with water, are physically demanding, or are cumbersome in the set up to prime the pump. Some pump arrangements may also require external sources of power such as compressed air or water flow to prime the system.
It is an object of the present invention to obviate these difficulties.